This invention relates to a method of producing an insulated gate field effect transistor by using a semiconductor substrate exhibiting a semi-insulating property.
A typical method of producing a conventional insulated gate field effect transistor comprises diffusing impurities into a p- or n-type conductive substrate to form source and drain regions, and forming a gate oxide film on the substrate surface between the source and drain regions. However, the use of such a conductive substrate brings about a large floating capacitance of the produced transistor, resulting in lowering of high frequency and high speed characteristics.